The invention is directed to a door fastener for motor vehicle doors comprising a door holding bar, which is supported at a door arrangement part, door or door post, and a holder which is fastened at another door arrangement part and is formed from a sheet metal blank which is shaped into a U-shaped housing. A torsion bar spring is supported in the holder via a shaft part and an abutment arm. In addition, an abutment roller is supported in the holder so as to be rotatable around a stationary axis. Furthermore, a loading roller is supported on a free loading arm of the torsion bar spring, and, finally, the two rollers cooperate with the oppositely located narrow sides of the door holding bar formed by means of a flat material blank.
In known door fasteners of this type, the abutment roller and the loading roller are supported on the fixed axis in the holder housing, on the one hand, and on the loading arm of the torsion bar spring, on the other hand, accompanied by the use of a thin layer of permanent lubricant in each instance. Such a support and lubrication results in the problem that the rollers tend to jam prematurely at the respective axis under the influence of environmental conditions, particularly by means of dust and condensation water precipitation, but also because of the consequences of long-term operation. Jamming is chiefly the result of the fact that the rollers often only execute a partial rotation and in so doing are also acted upon at constantly recurring points on their bearing circumference by very high loads resulting from the passage of the holding catches of the door holding bar. However, in door fasteners of the type in question, a roller which is not rotatable relative to its bearing axis or a roller which has become rotatable only with difficulty results in the roller grinding along the narrow side of the door holding bar assigned to it, so that a particularly loud and therefore highly undesirable noise results precisely in door fasteners because of the resonating effect caused by the door body. The use of a maintenance-free bearing via bushings or sleeves comprising maintenance-free bearing material is likewise faced by the problem of a recurring local high loading of the bearing at the same place on the bearing circumference in rollers which frequently execute only partial rotations. In many cases cost is also a factor in these types of bearings.